Fatal Errors while working in 3D

[pacman454]

I am new to the full version of AutoCad 2004 and am trying to build a 3d model. The program seems to be running very slow, the drawing is about 650 kb so far. Also I get a fatal error when trying to execute commands (move, copy, mirror, etc) One of the error I see is "Unhandled Access Violation Reading 0x2c1b49e4 Exception at 330291d4h". Any help would be greatly appreciated. Thank You.

 

[architech]

Could you be XREFing a bad file?
And what exatcly is your model?
And do you have mapped material?

 

[pacman454]

I have built this model from scratch
no XREF or mapping either
It is a swimming pool bulkhead (walkway)
composed of steel angle. It is faily large 4'x5'x75'
It seems if I work on it while it is shaded (instead of wireframe) I dont have near the amount of errors